The input JSON should be thought of as an hierarchy of predefined entities,
some of which correspond to a Python class used by StyleFrame.
The top-most level should be a list of sheet entities (see below).

"default_styles" - A JSON object with items as keys and style entities as values.
Currently supported items: headers and cells.

"default_styles":{"headers":{"bg_color":"blue"}}

"row_heights" - A JSON object with rows indexes as keys and heights as value.

"extra_features" - A JSON that contains the same arguments as the
to_excel method, such as "row_to_add_filters", "columns_and_rows_to_freeze",
"columns_to_hide", "right_to_left" and "allow_protection".
You can also use other arguments that Pandas’ "to_excel" accepts.